1. Technical Field
The present invention relates to a multi-interface card, and more particularly to a multi-interface case in which a smart card and a memory card are implemented, and a method of interfacing between the smart card and the memory card.
2. Discussion of Related Art
A smart card, for example a SIM (Subscriber Identification Module) card, may be coupled to a mobile phone, wherein the SIM card includes subscriber information such as subscriber's phone number and an authentication identification for enabling the mobile phone. The subscriber can use the mobile phone when the SIM card is coupled to the mobile phone.
The mobile phone needs to use both a SIM card for performing an authentication operation, and a memory card for storing multimedia data.
When the SIM card and at least one memory card are used in the mobile phone at the same time, the SIM card and the memory card are separately coupled to the mobile phone.
The SIM card and the memory card may operate at different clock rates. For example, the SIM card operates at a low clock rate, such as about 5 MHz, and the memory card operates at a high clock rate, such as about 20 MHz.
In addition, a SIM card host and a memory card host operate independently each other. The SIM card host and the at least one memory card host may adopt different power supply voltages, the power supply voltages of the SIM card host and the memory card host may be independently turned off, and may be simultaneously turned on. In addition, a reset request may be independently generated by the SIM card host or by the memory card host.
The multi-interface card cannot provide functionality for simultaneous access to the SIM card host and the memory card host. More particularly, the multi-interface card cannot simultaneously support the SIM card interface and the memory card interface operating at different clock rates.
When a plurality of interfaces are implemented, the multi-interface card cannot sense whether power supply voltages of the card hosts are turned off or on, whether the clocks of card hosts are stopped or running, or whether reset requests of the card hosts are activated or deactivated. Thus the multi-interface card cannot manage the multi-interface card system.
Therefore, a need exists for a multi-interface card supporting a smart card and a memory card.